For 4 people
Prepare the quinces by washing them, peeling them, removing the heart, as well as the hard parts that may not cook.
Using a grip press, extract the lemon juice and put it in a bowl or a bowl filled with cold water. Dice the diced quince pieces.
Drain the fruits, then put them with the rest of the ingredients in a jam pot or in a saucepan. Sugar can be replaced by 1 kg of giant sugar.
Cook over high heat, making sure to simmer 1 hour after boiling (10 to 15 minutes with giant sugar). Meanwhile, stir continuously using a spatula.
If necessary, foam the surface of the pot using a skimmer to remove the foam.
Once the consistency has been obtained (a jam flowing slowly on a flat plate), pour the jam into individual jars previously sterilized with boiling water.
To homogenize the contents of jam jars, install the cover and overturn for 1 minute.